homework02.html 1.1 KB

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  1. <!DOCTYPE html>
  2. <html>
  3. <head>
  4. <meta charset="UTF-8">
  5. <title></title>
  6. <style>
  7. * {
  8. margin: 0;
  9. padding: 0;
  10. }
  11. #container {
  12. margin: 10px 20px;
  13. }
  14. #container li {
  15. float: left;
  16. list-style: none;
  17. width: 60px;
  18. height: 60px;
  19. }
  20. </style>
  21. </head>
  22. <body>
  23. <div id="container">
  24. <img src="img/picture-1.jpg" alt="狗屎">
  25. <ul id="items">
  26. <li><img src="img/thumb-1.jpg" alt=""></li>
  27. <li><img src="img/thumb-2.jpg" alt=""></li>
  28. <li><img src="img/thumb-3.jpg" alt=""></li>
  29. </ul>
  30. </div>
  31. <script>
  32. var img = document.querySelector('#container>img');
  33. var images = document.querySelectorAll('#items img');
  34. for (var i = 0; i < images.length; i += 1) {
  35. // 事件回调函数在for循环的时候并没有执行所以也取不到循环变量i当前的值
  36. // JavaScript是动态弱类型语言可以在运行时动态的添加(或删除)对象的属性
  37. images[i].picture = 'img/picture-' + (i + 1) + '.jpg';
  38. images[i].addEventListener('mouseover', function(evt) {
  39. img.src = evt.target.picture;
  40. });
  41. }
  42. </script>
  43. </body>
  44. </html>